Electric system



June 24, 1930. J, CREVELlNG *l 1,766,490

ELECTRIC SYSTEM ofikinal Filed Dec. 7, 1925 INVENTR'.

Patented June 24, 1930 UNITED 4STATES Paxriau'rl OFFICE JOHN L. CREVEDING, OF NEAR TUCSON, ARIZONA, ASSIGNOR, BY MESNE ASSIGNMENTS,

T SIMPLEX EQUIPMENT COMPANY, IN., 0F NEW YORK, N. Y., A CORPORATION OF DELAWARE Application led December 7, 192.5, Serial No. 73,536. Renewed March 4, 1930.

' My invention relates to that class of electric systems wherein av dynamo or generator isv used to charge a storage battery and 0perate lamps or other translating devices it is a further object of my invention to so connect the generator and battery when their voltages are so nearly equal that they may be considered, in practice, as equal, and to cause this connection to be broken when the generator voltage fallsl so slightly below that of the battery that the back discharge through the generator is substantially negligible. A further object of my invention is to bring about such connection and disconnection of the generator and battery throughout wide variation in the battery voltage, as the voltage across the battery such systems often varies considerably depending upon the condition of the storage battery and upon its condition of charge at the particular moment of such connection. In practical operating systems, it is not unusual for the voltage across the battery to vary between 28 and 40 volts, or thereabouts; and, in the system of my present invention, I cause the connection and disconnection of` the generator to take placeat what may be considered, for all practical purposes, substantially equal volt.-

age, even throughout a much `wider range than this. It is a further object of my invention to use-a very slight current drawn from the battery and of so low value as not to form any appreciable drain thereupon, for the purpose of causing the generator tofbuild up properly when started, and to utilize this current for the purpose of.1 functioning in the operation of connecting and disconnectingthe generator and battery.

In the drawing, Fig. I is a diagrammatic representation of a system embodying the elements of my invention, the principal parts of which are shown in relatively large scale in front elevation; and

Fig. II is a side elevation of those parts illustrated in front elevation in Fig. I.

Fig. III is a diagram showing one modification that may be made in the arrangement of Fig. I.

In the drawing, referrnigaparticularly to Fig. I, 1 represents a dynamo or generator provided with a field coil 2 in series with Which there is placed a carbon pileB, and it will therefore be obvious that the generator may be regulated by properly manipulating the pile 3. -The positive brush of the generator is kconnected as by wire 4 with one end of the solenoid 5, the opposite end of which is connected with the coarse Winding or coil 6, the opposite end'of which is connected with a contact member 16. The winding 6 surrounds the core 7, of iron or other magnetic material, carried by the yoke 8 and secured thereto as by screw 9. l() is a permanent magnet having upper and lower extending poles, as shown plainly in Fig. II. The upper ex` tension may be used to support the yoke 8 and the parts carried thereby and may be attached to the said yoke as by means of screws 11. The yoke 8 carries a core, of iron or other magnetic material, 12, attached there to as by means of screw 13, similar to the core 7, which cores are preferably equally (spaced with respect to the center line of the magnet 10. A member 14, of brass or other non-magnetic material, is drilled with holes adapted to slip snugly. over the polar extensions of the cores 7 and 12, and is saw-slotted in a vertical plane extending toward the left from the opening surrounding the core 7, and toward the rightf'from the opening surrounding the core 12, in such manner that by tightening screws .15, tending to close the said saw-slots, the cores 7 and 12 may be pinched in such manner that the member 14 will be securely attached thereto audsupport the windings 6 and 18. One end ofthe membei' l4-car1ics the contact member 16 electrically connected with the winding 6 and insulated from'the member 14, as indicated. The opposite end of the member ,14 carries a contact member 17, insulated therefrom as indicated. The core 12 is surrounded by a relatively very fine winding, indicated at 18,v

the opposite'ends o f which are electrically connected with the contact members 16 and 17, one end of the winding 18 bein shown directly connected with 17, while t e opposite end is connected with one end of the coil 6,- which is the equivalent of connection directly with 16. i The member 14 is provided 'with downwardl extending lugs 19, carrying the adjustab e screws 20, forming a pivotal support for the armature or kee r 21, of iron orother magnetic material, w ich is drilled to receive the ends of said screws 20. The keeper 21 carries a ,conducting member 22 which may be insulated therefrom, if desired, said conductin member having secured in electrical connection therewith, at its opposite ends, the flexible brushes 23, so arranged that when the keeper 21s slightly rotated about its pivot in a clockwise direction the brushes 23 will cause electricalconnection between the contact 'members 16 and 17. If desired, an auxiliary contact member may be provided to insure contact between the brushes and the members 16 and 17 under exceedingly slight pressure. And, forthis urpose, there is indicated a flexible lea 24, in each brush .23, which extends slightly bend the other leaves of the said brushes,- it\being obvious that'a very thin leaf thus extendingmay cause electrical connection between 16 andy 17 to be established with very slight pressure, owing to the flexibility of said leaves; and it will also be obvious that any such auxiliary contacts may be omitted provided the main brushes 23 are roperly arranged so4 that they simultaneous y strike the contacts 16 and 17 The keeper 21 is provided with ad'ustable screws 25 and 26, which are made o brass or other non-magnetic marterial andwhich may limit the approach vof the ends of the keeper 21 toward the ma net-poles and 12. The keeper 21 and t e' parts carried thereby are all preferably balanced with respect to the pivots 20, which are preferably so arranged as to cause very little friction to resist rotation. Thus armature 21, being of reasonably small mass, may be swung from the position indicated in Fig. I to that causing electrical connection between the contacts 16 and 17 and vice versa,v with the expenditure of very little energy. The contact member 17` is connected, as ind icated, with the wire 27, carried to the ositive side of the storagebattery 28 an the positive side of the lamps or other translating devices indicated at 29, return from the lamps and battery being made to the generator as by wire 30. 31 is a voltage coil connected across the nerator and adapted when energized to teneto raise the core with `havin that ordinarily used incarlig which it is shown provided, and thus decrease the pressure upon the pile 3 and increase its resistance. The coil 5 is provided with a core, as shown, which it tends to raise when energized so-as to lessen the pressure upon the ile 3 and increase its resistance. The coi 5 and its cooperating parts so manipulate the resistance 3 that a given maximum generator current cannot be exceeded throughout speed chan es of the generator; while the coil 31 an ing parts so manipulate the pile 3 that a 'ven maximum voltage cannot be exceede by the generator throu hout speed changes.

As regulators for t is service are now wellknown in the art, one of this type is merely indicated here diagrammatically, for the sake of sim licity in illustration, it being understood t at an of the well-known regulators thefc aracteristics required may be used or the purpose.

32 is a resistance which may be placed across the generator through coil 6.

An operation of my invention is substantially as follows:

If the generator be at rest or operating at suiiiciently low speed, the contacts 16-23 and 17-23 will both be open and the battery 28 may supply theilamps or translating devices 29 in a well-known manner. Some current will flow from the positive side of the batter-sy through wire 27 to one end of the windin 1 thence through said windin to one en of Ithe coil 6, thence throu h t esaid coiland coil Y5 and wire 4 Lto -t e generator; from which it will return to the battery through the wire 30. And I so arrange the winding 18 and .the olarity of the permanent ma net 10 -that t is current flowing back throug the dgenerator, as above mentioned, tends to hol the keeper 21 in the position shown in the drawing by caus' thel right-hand side of the said keeper to strongly attracted by the core 12, the airgap between said core and the keeper being adjustable as byscrew 26. The small current flowing back through the magnet 18 thus locks the contacts 16-23 and 17-23 o n, as an extremely small cur-- rent will, wit the proper adjustments of the parte, exert a ve strong pull upon the rightand endl of the eeper. This small current owing back through the coil 18, employed, as above mentioned, to lock the contacts open, provides a verysmall flow lthrough the generator which serves to cause the same to build up (properly when it is started in operation, an is an inappreciable drain u n the battery and need not be an l ting systems for the purpose of causing the generator to build upmerely, said current usually being due to a high resistance shunt across the switch controlling the connection of the generator and storage battery,-a now wellknowncommon practice in such systems. If

its cooperatgreatert an current in the coil 18 will decrease and, when the voltageof the generator and battery are equal, there will be no current iowing in the said coil 18. As soon as the generator voltage exceeds that of the battery, the cur- ,i .rent inthe coil 18 will be reversed and then proper, establish such connection. If now the generator voltage be caused to appreciably exceed that of the battery, current will fiow from the generator through wire 4, coil 5, coil 6 contact 16-23, conducting member 22,I contact 23-17, wire 27, to the battery and translating` devices, and return to the generator through wire 30. And I so arrange tery andv translating devices increases.

the coil 6 that this current will now attract the left-hand end of the keeper 21 and cause a good contact to be established between the brushes 23 and the contact members 16 and 17; and it will be obvious that the pressure upon these contacts may be madeto increase as the current through the coil 6 to the bat- If now the generator voltage be increased and the generator tend to supply a current greater thandesired, coil 5 will cause the resistance 3 to be so manipulated as to prevent this desired maximum current from being exceeded. If, on the other hand, the voltage limited by the coil 31 be reached before suicient current is reached in the coil 5 to affect the resistance 3, the coil 31 will assume the regulating of v the generator and prevent this predetermlned volta e from belng exceeded. Thus the trans ating-devices may now be maintained by the generator and the battery may be charged in conjunction therewith, if the system e properly arranged for this purpose. If now the generator be slowed down until its voltage is nearly equal to that of the battery, a very small current will flow through the coil 6; and, if the generator voltage be allowed to fall slightly. below that' of the battery, the battery will discharge back through the, coil 6, and thus, by reversing its effect upon the magnetic flux through the core 7 cause the keeper 21 to be revolved in a counter-clockwise direction into the position shown in the drawing, and the connection between thegenerator and battery broken at the contacts 16-23 and 17-23. The voltage of the generator now being slightly below that of the battery, avery feeble current will llow back through the coil 18 and hold the switch in this position in which it is shown in the is required in the coil 18 to rotate the keeper 21 in a clockwise direction and close the contacts 16-23 or 16-24 and 17-23 or 17-24, that the generator and battery may be connected automatically at so near the same voltage as to be, for most practical purposes, the equivalent of the same voltage; while I also iind that the back discharge through the coil 6, necessary to cause the contacts 16-23 and 17-23 to be opened, is so small that it may be called a negligible or practically zero back discharge, it, of course, being noted that the members 7, 8, 12 and 21 'are preferably of material` having a low reluctance and exhibiting as little hysteresis as possible so that the iuxes may be readily affected by ver small changes in magnetomotive force. n practice, ffind that by employing a small load upon the generator through the coil 6, while the generator is still disconnected from the battery, I may cause the connection between-the generator and battery to be so adjusted as to take place as nearly upon equal voltages as may be desired; for, it will be noted that while the generator is at rest and disconnected from the battery there will be no current flowing through the resistance 32, while as soon las the generator electromotive force builds up some current will flow from the positive brush through wire 4, coil 5, coil 6 and resistance 32 tothe negative brush of the generator. This` current through coil 6 is in the same direction as that supplied by the generator to the lamps and battery and, therefore, tends to cause the keeper 21 tol rotate clocks wise and close the connection between the generator and the battery. By properl adjusting the value of the resistance 32, can so adjust this current in the coil 6 that, when the voltage of the battery and generator are substantially equal, this' current in the coil 6 will be suiicient, or nearly suilicient, as may be adjusted, to cause the keeper21'to close the contacts 16-23 and 17-23 when `a le to use a very small load in' the coil 6, in

this manner, which need not be more than enough to overcome the hysteresis effect in order to cause the generatorand battery to be connected at what may be considered equal voltages, for all practical purposes, even Where considerable refinement is desired.

The current thus employed through the coil 6 may be so small that its effect upon the back -lamp of proper resistance, and such a amp ma be made to perform any useful function, such as indicating when the generator is operating. r, if desired, any type of an indicating instrument of proper resistance may be employed at 32 which may serve to` indicate the operation of the nerator. It will further be obvious that i any other coil or generator current-using or voltage-measuring device in the system may be arranged so as to have the roper resistance, it ma be used in lace of t e resistance shown at 2. That is, if the coil 31, for example, be of proper resistance and its end, (now, shown connected to the upper, end of the winding 6). be connected with the lower end of said winding instead, as shown in Fig. III it may be used to perform the function o the resistance 32. Further, it will be 8 0 plain that the current thus flowing through the windi 6 may be so adjusted, by properly adjusting the load indicated` at 32, that the keeper 21 may be caused to rotate in a clockwise direction and close the `contacts 16-23 and 17-23 at a littlejbelow zero volt- 4 -co' 6 and age across coil 18, if` desired, or to cause the keeper to be revolved andl close the contacts .at zerovoltage across 18, if the keeper 21 and parts carried thereb'y'be so arranged as to be out of balance 'd biasedby the force of gravity so as to tend to assume the position shown in the andy open the contacts 416-,23and 17-23 `oii account of the action of or its uivalent, whenever both 18 arcade-energized. Withuthisi, latter arrangement, the contacts can always" be caused toopen when 'the generator is below a predetermined voltage, even though a battery lead be 'broken in such manner as to render. the coilv 18 unable to rform its usual function in connection with thetbatte f v l lt will also be obvious that the switch, as indicated in Fig. I as open, will close when the generator starts up, even if a battery lead be roken, provided there is any load upon the circuit, such as lamps 29, since current will vity flow from the nerator through the winiin 18 :lilid the lo to the wire 30 and thence bac t0 e Lgleiierator; andthis current traversing the co 18 will be in the direction to close the switch, which will operate to so act on account of the permanent lield set up by the magnet 10. It will also be obvious that if the armature 21 be balanced, as lis usual breaki with this construction, the residual magnetism set u traverse ,t e magnet 6, will have a .tendency to hold the switch closed under such conditions, since there will be no back discharge from the battery to reverse the residual effect when the generator slows down and stops. In either event, the lamps'if thrown on will be sup lied by the generator while running. At rst glance Vit; would appear that i with a broken battery lead, he switch should tendto remain closed, due to the slight residual-magnetism, trouble would be encountered if the batteries werel reconnected during a stop. This, however, is not the case, since it is always the custom, in connectin a storage battery into a circuit which mig t have a load upon it, to tap the connectors quickly together to see if a spark, indicating a loa ensues. This instantaneous o and of the circuit, which is .a common habit with all battery men, serves to kick the switch o n and reverse the residual magnetism soat it remains open, and the connection can be made without any trouble ensuing. 4

Therefore, in my system, the generator is connected with the battery whenvtheir voltagles are practically equal, and disconnected w en their voltages are also practicall equal, regardless of what the'vol of the' attery may be within predetermin very wide limits; and the action of opemng and closing the contacts, even though roug t about by extremely small di'erences in voltage between the neratorand battery, is, nevertheless,

itive and not of an unstable or chatterin nature. t

ile I have'described the ends ofthe coil 18 as connected, in eect, directly across the contact members 16 and 17, so that current flowing back te the nerator thro also flows throu` h t e coil 6 which contains only relatively ew turns of heavy wire, the left-hand end of the coil 18 ma readily be connected to the other end of coil 6 so that the current going back from the battery .to the generator thro h coil 18 does not circulate ,through the co' 6, if desired,a connection which may be found preferable, if desired that the eect of the coil 6 under current carried by the coil 18 be eliminated.

I do not wish in any way to limit myself to any of the details of construction or modes ration herein given to illustrate an embodiment of my invention, for it will be obvious that wide departure inthe way of details, both in construction and operation may be made without departing the spirit and scope ofy my invention `which is as set forth in the following claims:

1. The combination with a generator, a storage battery charged thereby and means for connecting said generator and batte means operated to cause such connection y a ugh il is4 by the load current, which will l ios cuio

coil in shunt around said connection and a coil in series with said connection having a material effect in causing said connect-ion.

2. rIhe combination witha generator, a storage battery charged thereby and means for connecting said. generator and battery, of means for causing said connection operated by a coil across said connectionand means for causing disconnection usefully cooperating therewith in the causing of said connection.

3. The combination with a generator and a storage battery charged thereby, of means for connecting and disconnecting the generator and battery comprehending contact mechanism and a voltage coil in shunt around the contact thereof for operating said mecha- -nism to cause connection of the generator and battery in cooperation with an independently excited coil in series with said contact and materially affecting the closing thereof.

4. The colnbination with a generator and a storage battery charged thereby, of means for connecting and disconnecting the generator and battery comprehending contact mechanism and a voltage coil in shunt around the contact thereof and a coil in series with said contact functionally cooperating therewith in operating vsaidmechanism to close said contact. A

5.' r1 he combination with a generator and a storage battery charged thereby, of means for connecting and disconnecting the generator and battery comprehending contact mechanism and a voltage coil in shunt around the contact thereof for operating said mechanism to close said contact, and means cooperating therewith affected by the operation of the generator for opening said contact and functionally participating in the closing of the same.

6. The combination with a generator and a storage battery charged thereby, of means for controlling the connection therebetween comprising contact mechanism, a rotatable ma netic member for controlling the same an a mavnet for aecting the operation of' Said member in. shunt across the contact of said mechanism and a magnet in series with said contact for closing the same.

7. The combination with a generator and a storage battery charged thereby, of means yfor controlling the connection therebetween comprising contact mechanism, a movable magnetic member for controllin the same, a winding for affecting said mem er in shunt across the contact of said mechanism and a winding in series with s'aid contact eecting the closing thereof.

8. The combination with a generator and a storage battery charged thereby, of means for controlling the connection therebetween comprising contact mechanism, a movable magnetic member for controlling the same, a winding for closing said contact in shunt around said contact and a winding for opening said contact in series therewith controlling the closing thereof.l

9. The combination with a generator and a storage battery charged thereby, of means for controlling the connection therebetween comprising contact mechanism, a movable magnetic member for controlling the same, a winding for closing said contact in shunt around said contact, a winding for opening said contact in series therewith, and means whereby said last-named winding aects the point of closing of said contact.

10. The combination with a generator and a storage battery to be charged thereby and means for connecting and disconnecting the generator and battery including a contact, of a movable magnetizable means for controlling. said contact, a winding for affecting the movement thereof and in shunt around said contact and a winding in series with said contact functionally affecting the closing thereof.

11. The combination with a generator, a

storage battery charged thereby and means for connecting and disconnecting the generator and battery, of a winding for affecting the said means normally ineffective while the battery and generator are connected and effective during disconnection thereof, and a winding in series with the generator and battery when connected and functionally operative in the connection of the battery and generator under the influence of -current flowing therethrough' which is unaffected by the connection and disconnection of the battery and generator.

12. The combination with a generator, a storage battery and means for connecting and disconnecting the generator and battery including a contact, of means for controlling 4 said contact including a winding in shunt around the contact and a winding in series with the contact functionall affecting the closing thereof under the in uence of a material current from the generator and independent of the battery.

13. The combination with a generator, a storage battery and means for connecting and disconnecting the generator and battery including a contact, of means for controlling said contact including a winding in shunt around the contact and a winding in series with the contact functionally affecting the closing thereof under the infiuence of a material current from th'e generator, which current4 further affects the operation of the generator.

14.The combination with a generator, a storage battery to be charged thereby and means for connecting the generator and battery comprising a contact, of means for making and breaking said contact comprising a rotatable magnetic member having `magnet cores on each side of its center of rotation and separated from said member by an air gap, means tending to cause a magnetic flux through said magnetic member and both said cores, a winding u n one of said cores connected around sai contact, and a wind` upon the other core in series with the consite si tact.

15. The combination with a enerator, a storage battery to be charged t ereby and means for connecting the generator and battery com rising a contact, of means for making and reaking said contact comprising a rotatable Ama etic member, vwindings situated u on eac side of the center of rotation of sai magnetic member, and means tending to cause a magnetic iux through said member and linking said windings, one of said windings being connected around said contact and the other in series therewith. l

16. The combination with a generator and ra'. Stora battery to be charged thereby, of means or causing connection and disconnection of the generator and battery including a rotatable member for operatin said means havin electro-magnets situate upon oppodes of its center of rotation, means tending to cause a ma etic flux through said rotatable member gam its center of rotation toward said magnets and linked with the windings thereof, one of said electro-magnets having a winding permanentl coiinecti the generator and battery and't e other having a winding carrying useful current supphed b the generator to the battery.'

17. e combination with a generator, a storage battery to be charged thereby and means for connecting the generator and battery com risinga contact, of means for making'and reaking said contact comprising a movable magnetic membgr having magnet cores on each side of its center and separated from said member by an air gap, means tending to causev a magnetic flux through said magnetic member and both said cores a winding upon onesof said coresconnected around said cpntact, and a winding upon the other core inseries with the contact.

18. The combination with a generator, a storage battery to be charged thereby and means for' connecting the generator and bal(- tery com rising a contact, of means for making and reaklng said contact compr' a rotatable magnetic member, windings situated u on each side of the center of rotation of sai magnetic member, and means tending to cause a magnetic flux through said member and-linking said windings, one of said windings being connected around said contact and ,the other in ,series therewith, said windings cooperating with said flux to rotate said member.

19. The combination with a generator, a

` storage batte to be charged thereby anda load circuit supplied by the generator and battery, of means for causing connection and disconnection of the generator and battery including a rotatable member for operatin said means having electro-magnets situated upon opposite sides of its center of rotation, means tending to cause a magnetic ux through said rotatable member from its center o rotation toward said magnets and linked with the windings thereof, one of said electro-magnets having a winding rmanently connecting the generator and gsttery and the other havingv al windin normally carrying useful current supplied by the generator to the battery one of said windings cooperating with said ilux to close said contact when the generator is runnin and the battery is inoperative and there is a oad upon the load circuit. i

JOHN L. CREVELING. 

